Improvement in electro-magnetic dental pluggers



, G. F. GREEN.v

ELECTRO MAGNETIC DENTAL P'LUGGERS.

No.171,1 19. yPatented. Dec.14,1875.

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la 'S *AAM "PETERS, FMOTGLITMOGRAPHAER. WASHINGTON. l)v C.

'UNITED STATES PATENT GEEIcEc GEORGE F. GREEN, KALAMAZOO, MICHIGAN, ASSIGNOR TO SAMUEL S. WHITE, OF PHILADELPHIA, PENNSYLVANIA.

IMPRQVEMENT IN ELECTRO-MAGNETIC DENTAL PLUGGERS.

Specification forming part of Letters Patent No. 171,119, dated December 14, 1875; application filed August 5, 1873.

CASE F.

To all whom it 'may concern:

Be it known that I, GEORGE F. GREEN, of

Kalamazoo, Michigan, have invented certain Improvements in Electro Magnetic Dental Mallet Pluggers, of which the following is a specification, reference being had to the accompanying drawings, in which- Figure l represents a side elevation of my improved instrument; Fig. 2, a vertical longitudinal section through the same; and Figs. 3 and 4 are views, showing details.

My invention relates to dental malletfpluggers of that class (originated by me) in which electro-magnetism constitutes the sole motor.

I construct a frame, A, in the general form of a pistol-stock, so that it may be conveniently held in the hand, the two bars aand b, which constitute part of this frame, being coucaved and curved, so as to afford bearingsurtaces for the support, and enlarged spaces for the operation, ofthe moving parts. These bars are connected at their upper ends to a barrel or tube, B, which is held horizontally in a relation similar to that of the barrel of a pistol. A circular or horseshoe-shaped magnet, C, is rfastened by its closed end or oenpoles in a vertical position toward the front of the stock. The lower end of the stockbar bis secured to thelo'wer pole C1 of the magnet, and to the barrel B. The bars a b and the magnet thus compose the frame.

Upon the upper part of the magnet I form a ange or projection,D, on which I fix eyes n s, and to these eyes. I connect the wires of the battery.

On the upper pole C2 of the magnet I form lugs, through which pivots are passed to support the mallet E, which swings on these pivots, as shown in the drawings. An ear, d, on the stock-bar b coincides with the lugs,

and, the pivot-bolt passing through this ear,

gives an additional point of bracing for the frame.

The mallet consists of a shaft or handle, c, the upper end of which is provided with a hammer-head of suitable weight, the lower `end carrying the armaturemF, and is further between the poles of the magnet, while the hammer plays upon the inner end ofthe spindle which carries the tool, as will presently be further described. A spring, f, is connected with the mallet-shai't, and tends to hold the armature away from the magnet.

I have devised for this instrument an automatic circuitbreaker, the construction and operation of which is as follows:

I attach a spring, g, to the shaft of the mallet, near the armature, and extend this spring `forward toward the hammer, mounting on its free end a wheel, h, which will be most conveniently located about opposite the pivot of the mallet.

I secure upon the inside of the stock a circuit-breaker block, t', arranging it and deining the length of the spring g, so that the wheel h will alternately traverse the inclined surfaces as the head of the lnallet Vibrates. The block is thus vibrated by the spring g, and 011e end of it comes in. contact with a wire connected to the eyes n s.

Whenever this contact occurs the circuit is closed, the armature is brought toward the magnet, and the hammer strikes; then the wheel h ou the spring g, passing Athe point of the breaker-block c', throws it away from the wire, and breaks the circuit.

Inasmuch `the spring j' will constantly tend to press the armature away from the magnet, and the hammer-head away from the barrel B, it will be seen that'the normal position of this springfwill be such as to oonstantly press the block i against the wire, or,

in other Words, the spring g will tend to mainthe end of the barrel, so that it is interposed between the hammer and the end of the barrel. By moving this plate in or out the lip is brought nearer to or farther from the base of the barrel, and the blow of the hammer is more or less received upon the lip, which thus 4acts as a brake to regulate the extent to which the force of the blow is delivered upon the spindle of the plugging-tool.

I provide a screw-gage, G, around the barrel B, by means of which the position of the lip and the force of the blow may be adjusted, as seen in Eig. 2. I also, by preference, interpose a coiled spring, e, in the end of the barrel B, between the end of the spindle and the hammer-head, to assist, by its resilience, in throwing thehammer-head back when the circuit is broken.

In what would be about the nipple of the pistol-barrel B I insert what I call pads m a, for closing and breaking the circuit, by simple pressure upon the point of the instrument. The barrel B is tapered gradually from thebreech to the muzzle, and in this cas-- ing, and protruding through the inuzzle, I insert the spindle H, the outer end ot' which is socketed to receive the plugging-tool, while its inner end extends back, and protrudes through the breech, and receivesthe blow Hoi" the hammer, as already described.

Toward the lower end'ot the spindle I fix on it a collar, O, which bears against the up- 'g per plate of the pads, above referred to.

These pads consist of two metallic pieces, of uniform contiguration, one end ot' each having in it a hole, through which the spindle H passes. These pieces have shanks or tongues which are bent downward, and separated at the points by means of any suitable non-conductor.

` I have -used pasteboard between the two metallic pieces, and wrapped thread around the pieces (with the pasteboard between) to insulate these two pads, and yet keep them 011 each side'of the insulator, close together.

insert these pads in the barrel about the nipple, as above stated, so that the perforated ends of the pads shall lie across the barrel, parallel' with each other, while their shanks extend through the casing, and afford points ofattachment for Wires, which are to be connected with the battery and with the circuit-breaker block, already described. (See Fig. 2.)

New, as the spindle H passes through the perforated ends vot' these pads, and as it carries the tool on its upper or outer end, it is manifest that any pressure upon the end of the plugging-tool will compress the perforated ends ot' the pads together, until they come in contact, whereupon the circuit is closed. (through the other ends ot' the pads and the wires connected therewith,) and the hammer will strike as long as the spindle thus presses on the pads. Whenever the pressure 0n the spindle is removed, the pads will spring apart again with the forward movementof the spindle, and break the circuit, stopping the blows of the hammer.-

I provide for the graduation of the pressure required to press the pads together, as it will be desirable to have this pressure great-A er at one time than at another, by putting a coiled spring, p, within the barrel at its up-4 per end, and below this spring a shoulder, q, which may be moved up toward the spring by means of the screw-band r moving the studs s, which is ixed in the shoulder, and projects through the slottL in the casing, and as the spring is thus compressed the resistance of the point of the. plugging-tool will be increased.

In case it is desirable, this pressure may be made such as to prevent the closing of the circuit, and admit ot' the temporary use of the instrument as a hand-plugger.

It is also desirable to have the pluggingtool turned so as to bring its point or edge to bear in different positions upon the tooth, and I provide for this by making the upper section of the barrel vB to turn loosely on the lower section, and permit this change of position of the tool by locking the two sections together, by means of a flanged plate or simple pin passing through the outer casin g, and taking into a groove, c, on the end of the inner section, so as to allow the one to rotate within the other.

The spindle'H is held 'in the casing by abars a b, the barrel B, and the electro-magnet C, substantially as described.

2. The combination, with the magnet C, of the armature, connected with the mallet, to serve as a counter-balance thereto, and pivoted upon the magnet, and vibrating between its poles, substantially as described.

3. The combination ot' the frame A, the barrel B, the casing, and the reciprocating spindle H, substantially as described.

4. The combination of the frame, the barrel, the casing, the spindle, the mallet, the ar1nature, and the magnet, substantially'as and for the purposes described.

5. The combination of the hammer-head,

the combined counter-weight and armature,

the mallet-shat't, and the magnet, substantially as described.

6. rIhe cushioning-slide 7c, in combination with the hammer and spindle, substantially as described.

7. The combination, with the fixed barrel B, of the rotating section of the casing and the pistol-stock-shaped case A, substantially In testimony whereof I beve hereunto suhas l.rnd for the purpose described. scribed my na-me.

8. The combination of the mallen and armat-ure, connected directly together, as set GEORGE F. GREEN. forth, whereby the armature forms the coun- Witnesses: l ter-balance for the mallet, for the purpose LEVI TEAL,

specified. WM. E. MORGAN. 

